Breastfeeding and infant growth in offspring of mothers with hyperglycaemia in pregnancy: The pregnancy and neonatal diabetes outcomes in remote Australia study

BACKGROUND

Benefits of breastfeeding on infant growth in children born to mothers with gestational diabetes mellitus (GDM) are uncertain.

OBJECTIVES

To describe growth trajectories between birth and 14 months according to breastfeeding and maternal hyperglycaemia in pregnancy, and assess associations between breastfeeding and 14 month growth outcomes among children born to mothers with GDM.

SUBJECTS/METHODS

Data on 258 Aboriginal and Torres Strait Islander infants from the PANDORA study born to mothers with normoglycaemia (n = 73), GDM (n = 122), or with pre-existing type 2 diabetes (n = 63) in pregnancy were assessed. Infant weight and BMI growth trajectories according to predominant breastfeeding at 6 months and hyperglycaemia in pregnancy were developed using mixed-effect models and cubic splines. Associations between breastfeeding and 14-month growth outcomes (z-scores: weight-for-age, weight-for-length and BMI) were evaluated using linear regression in a subgroup of infants born to mothers with GDM.

RESULTS

Predominantly breastfed infants had lower BMI trajectories compared to those not predominantly breastfed, irrespective of maternal hyperglycaemia in pregnancy status (p < 0.01 for all groups), and lower weight trajectories among those born to mothers with GDM (p = 0.006). Among offspring of women with GDM, predominant breastfeeding was only associated with lower weight-for-age at 14 months, however adjusting for maternal obesity, smoking, and parity attenuated observed associations. Maternal obesity remained significantly associated with greater infant growth.

CONCLUSIONS

Predominant breastfeeding was associated with reduced growth among children born to women with and without hyperglycaemia in pregnancy. However, among children exposed to GDM in utero, maternal obesity largely explained this association.

Type 2 diabetes after a pregnancy with gestational diabetes among first nations women in Australia: The PANDORA study

AIMS

To determine among First Nations and Europid pregnant women the cumulative incidence and predictors of postpartum type 2 diabetes and prediabetes and describe postpartum cardiovascular disease (CVD) risk profiles.

METHODS

PANDORA is a prospective longitudinal cohort of women recruited in pregnancy. Ethnic-specific rates of postpartum type 2 diabetes and prediabetes were reported for women with diabetes in pregnancy (DIP), gestational diabetes (GDM) or normoglycaemia in pregnancy over a short follow-up of 2.5 years (n = 325). Pregnancy characteristics and CVD risk profiles according to glycaemic status, and factors associated with postpartum diabetes/prediabetes were examined in First Nations women.

RESULTS

The cumulative incidence of postpartum type 2 diabetes among women with DIP or GDM were higher for First Nations women (48%, 13/27, women with DIP, 13%, 11/82, GDM), compared to Europid women (nil DIP or GDM p < 0.001). Characteristics associated with type 2 diabetes/prediabetes among First Nations women with GDM/DIP included, older age, multiparity, family history of diabetes, higher glucose values, insulin use and body mass index (BMI).

CONCLUSIONS

First Nations women experience a high incidence of postpartum type 2 diabetes after GDM/DIP, highlighting the need for culturally responsive policies at an individual and systems level, to prevent diabetes and its complications.

Qualitative insights into Australian consumers' views for and against government action on sugary drinks

OBJECTIVES

Despite significant evidence of harms associated with high levels of sugar-sweetened beverage (SSB) consumption, and international moves towards regulation to curb overconsumption of such drinks, Australia has been slow to take policy action. This study provides in-depth insights into consumers' reactions to different SSB policy options.

METHODS

Eight focus groups were undertaken with 59 regular SSB consumers and/or household purchasers, stratified by: young adults aged 21-29 years (no children), parents aged 35-50 (with children at home); gender; and socio-economic status. Consumer responses to potential government intervention and policy options were explored using thematic analysis.

RESULTS

Three main themes were identified. Theme 1 describes participants' changing views on regulation of SSBs throughout the focus groups, expressed through shifts in understandings of personal responsibility and the role of government. It was noted that the term 'regulation' should be used judiciously, as it was widely misunderstood to infer bans. Theme 2 articulates the participants' preference for child-focused measures and educative measures such as clearer front-of-pack labelling. Taxation on SSBs was viewed more favourably if paired with investment into education. Theme 3 describes the parallels that participants drew between SSBs and other substances.

CONCLUSIONS

A comprehensive approach that includes education, child-focused interventions and regulatory approaches may increase acceptability of policy measures to curb overconsumption of SSBs.

Associations of gestational diabetes and type 2 diabetes during pregnancy with breastfeeding at hospital discharge and up to 6 months: the PANDORA study

AIMS/HYPOTHESIS

Women with gestational diabetes mellitus (GDM) and obesity experience lower rates of breastfeeding. Little is known about breastfeeding among mothers with type 2 diabetes. Australian Indigenous women have a high prevalence of type 2 diabetes in pregnancy. We aimed to evaluate the association of hyperglycaemia, including type 2 diabetes, with breastfeeding outcomes.

METHODS

Indigenous (n = 495) and non-Indigenous (n = 555) participants of the Pregnancy And Neonatal Diabetes Outcomes in Remote Australia (PANDORA) cohort included women without hyperglycaemia in pregnancy (n = 222), with GDM (n = 684) and with type 2 diabetes (n = 144). The associations of hyperglycaemia in pregnancy and breastfeeding at hospital discharge, 6 weeks and 6 months post-partum were evaluated with logistic regression, after adjustment for maternal obesity, ethnicity, maternal and neonatal characteristics.

RESULTS

Indigenous women were more likely to predominantly breastfeed at 6 weeks across all levels of hyperglycaemia. Compared with women with no hyperglycaemia in pregnancy, women with type 2 diabetes had lower odds for exclusive breastfeeding at discharge (adjusted OR for exclusive breastfeeding 0.4 [95% CI 0.2, 0.8] p = 0.006). At 6 weeks and 6 months, the relationship between type 2 diabetes and predominant breastfeeding was not statistically significant (6 weeks 0.7 [0.3, 1.6] p = 0.40, 6 months 0.8 [0.4, 1.6] p = 0.60). Women with gestational diabetes were as likely to achieve predominant breastfeeding at 6 weeks and 6 months as women without hyperglycaemia in pregnancy.

CONCLUSIONS/INTERPRETATION

Indigenous women had high rates of breastfeeding. Women with type 2 diabetes had difficulty establishing exclusive breastfeeding at hospital discharge. Further research is needed to assess the impact on long-term breastfeeding outcomes. Graphical abstract.

Social and economic factors, maternal behaviours in pregnancy and neonatal adiposity in the PANDORA cohort

BACKGROUND

Australian Indigenous women experience high rates of social disadvantage and type 2 diabetes (T2D) in pregnancy, but it is not known how social factors and maternal behaviours impact neonatal adiposity in offspring of women with hyperglycaemia in pregnancy.

METHODS

Participants were Indigenous (n = 404) and Europid (n = 240) women with gestational diabetes mellitus (GDM) or T2D in pregnancy and their offspring in the Pregnancy and Neonatal Diabetes Outcomes in Remote Australia (PANDORA) study. Social, economic factors, and maternal behaviours were measured in pregnancy and six neonatal anthropometric outcomes were examined after birth.

RESULTS

On univariate analysis, maternal education < 12 years (p = 0.03), unemployment (p = 0.001), welfare income vs no welfare income (p = 0.001), lower area based socio-economic score (p < 0.001), and fast food intake > 2 times/week (p = 0.002) were associated with increased sum of skinfolds (SSF) in offspring. Smoking was significantly associated with a reduction in anthropometric measures, except SSF. In multivariable models adjusted for ethnicity, BMI and hyperglycaemia, social and economic factors were no longer significant predictors of neonatal outcomes. Smoking was independently associated with a reduction in length, head circumference and fat free mass. Frequent fast food intake remained independently associated with SSF (β-coefficient 1.08 mm, p = 0.02).

CONCLUSION

In women with hyperglycaemia in pregnancy, social factors were associated with neonatal adiposity, particularly skinfold measures. Promoting smoking cessation and limited intake of energy-dense, nutrient-poor foods in pregnancy are important to improve neonatal adiposity and lean mass outcomes. Addressing inequities in social and economic factors are likely to be important, particularly for Indigenous women or women experiencing social disadvantage.

Cord blood metabolic markers are strong mediators of the effect of maternal adiposity on fetal growth in pregnancies across the glucose tolerance spectrum: the PANDORA study

AIMS/HYPOTHESIS

We aimed to assess associations between cord blood metabolic markers and fetal overgrowth, and whether cord markers mediated the impact of maternal adiposity on neonatal anthropometric outcomes among children born to Indigenous and Non-Indigenous Australian women with normal glucose tolerance (NGT), gestational diabetes mellitus (GDM) and pregestational type 2 diabetes mellitus.

METHODS

From the Pregnancy and Neonatal Outcomes in Remote Australia (PANDORA) study, an observational cohort of 1135 mother-baby pairs, venous cord blood was available for 645 singleton babies (49% Indigenous Australian) of women with NGT (n = 129), GDM (n = 419) and type 2 diabetes (n = 97). Cord glucose, triacylglycerol, HDL-cholesterol, C-reactive protein (CRP) and C-peptide were measured. Multivariable logistic and linear regression were used to assess the associations between cord blood metabolic markers and the outcomes of birthweight z score, sum of skinfold thickness (SSF), being large for gestational age (LGA) and percentage of body fat. Pathway analysis assessed whether cord markers mediated the associations between maternal and neonatal adiposity.

RESULTS

Elevated cord C-peptide was significantly associated with increasing birthweight z score (β 0.57 [95% CI 0.42, 0.71]), SSF (β 0.83 [95% CI 0.41, 1.25]), percentage of body fat (β 1.20 [95% CI 0.69, 1.71]) and risk for LGA [OR 3.14 [95% CI 2.11, 4.68]), after adjusting for age, ethnicity and diabetes type. Cord triacylglycerol was negatively associated with birthweight z score for Indigenous Australian women only. No associations between cord glucose, HDL-cholesterol and CRP >0.3 mg/l (2.9 nmol/l) with neonatal outcomes were observed. C-peptide mediated 18% (95% CI 13, 36) of the association of maternal BMI with LGA and 11% (95% CI 8, 17) of the association with per cent neonatal fat.

CONCLUSIONS/INTERPRETATION

Cord blood C-peptide is an important mediator of the association between maternal and infant adiposity, across the spectrum of maternal glucose tolerance.

Pregnancy And Neonatal Diabetes Outcomes in Remote Australia: the PANDORA study-an observational birth cohort

BACKGROUND

In Australia's Northern Territory, 33% of babies are born to Indigenous mothers, who experience high rates of hyperglycemia in pregnancy. We aimed to determine the extent to which pregnancy outcomes for Indigenous Australian women are explained by relative frequencies of diabetes type [type 2 diabetes (T2DM) and gestational diabetes (GDM)].

METHODS

This prospective birth cohort study examined participants recruited from a hyperglycemia in pregnancy register. Baseline data collected were antenatal and perinatal clinical information, cord blood and neonatal anthropometry. Of 1135 women (48% Indigenous), 900 had diabetes: 175 T2DM, 86 newly diagnosed diabetes in pregnancy (DIP) and 639 had GDM. A group of 235 women without hyperglycemia in pregnancy was also recruited.

RESULTS

Diabetes type differed for Indigenous and non-Indigenous women (T2DM, 36 vs 5%; DIP, 15 vs 7%; GDM, 49 vs 88%, p < 0.001). Within each diabetes type, Indigenous women were younger and had higher smoking rates. Among women with GDM/DIP, Indigenous women demonstrated poorer birth outcomes than non-Indigenous women: large for gestational age, 19 vs 11%, p = 0·002; neonatal fat 11.3 vs 10.2%, p < 0.001. In the full cohort, on multivariate regression, T2DM and DIP were independently associated (and Indigenous ethnicity was not) with pregnancy outcomes.

CONCLUSIONS

Higher rates of T2DM among Indigenous women predominantly contribute to absolute poorer pregnancy outcomes among Indigenous women with hyperglycemia. As with Indigenous and minority populations globally, prevention or delay of type 2 diabetes in younger women is vital to improve pregnancy outcomes and possibly to improve the long-term health of their offspring.

Performance of cardiovascular risk prediction equations in Indigenous Australians

OBJECTIVE

To assess the performance of cardiovascular disease (CVD) risk equations in Indigenous Australians.

METHODS

We conducted an individual participant meta-analysis using longitudinal data of 3618 Indigenous Australians (55% women) aged 30-74 years without CVD from population-based cohorts of the Cardiovascular Risk in IndigenouS People(CRISP) consortium. Predicted risk was calculated using: 1991 and 2008 Framingham Heart Study (FHS), the Pooled Cohorts (PC), GloboRisk and the Central Australian Rural Practitioners Association (CARPA) modification of the FHS equation. Calibration, discrimination and diagnostic accuracy were evaluated. Risks were calculated with and without the use of clinical criteria to identify high-risk individuals.

RESULTS

When applied without clinical criteria, all equations, except the CARPA-adjusted FHS, underestimated CVD risk (range of percentage difference between observed and predicted CVD risks: -55% to -14%), with underestimation greater in women (-63% to -13%) than men (-47% to -18%) and in younger age groups. Discrimination ranged from 0.66 to 0.72. The CARPA-adjusted FHS equation showed good calibration but overestimated risk in younger people, those without diabetes and those not at high clinical risk. When clinical criteria were used with risk equations, the CARPA-adjusted FHS algorithm scored 64% of those who had CVD events as high risk; corresponding figures for the 1991-FHS were 58% and were 87% for the PC equation for non-Hispanic whites. However, specificity fell.

CONCLUSION

The CARPA-adjusted FHS CVD risk equation and clinical criteria performed the best, achieving higher combined sensitivity and specificity than other equations. However, future research should investigate whether modifications to this algorithm combination might lead to improved risk prediction.

Chronic condition risk factor change over time in a remote Indigenous community

INTRODUCTION

This study sought to determine change in chronic condition risk factors in a remote Indigenous community following a 3-year period of community-led health promotion initiatives.

METHODS

Data were compared between two cross-sectional surveys of Indigenous Australian community residents before and after health promotion activities, and longitudinal analysis of participants present at both surveys using multilevel mixed-effects regression.

RESULTS

At baseline, 294 (53% women; mean age 35 years) participated and 218 attended the second survey (56% women, mean age 40 years), and 87 attended both. Body composition, blood pressure and urinary albumin-to-creatinine ratio remained stable between baseline and follow-up. After adjusting for age and sex, haemoglobin A1c significantly increased (from 57 to 63 mmol/mol (7.5% to 8.1%), p=0.021) for those with diabetes. Increases were also observed for total cholesterol (from 4.4 to 4.6 mmol/L, p=0.006) and triglycerides (from 1.5 to 1.6 mmol/L, p=0.019), and high-density lipoprotein cholesterol levels improved (from 0.98 to 1.02 mmol/L, p=0.018). Self-reported smoking prevalence was high but stable between baseline (57%) and follow-up (56%). Similar results were observed in the longitudinal analysis to the cross-sectional survey comparison.

CONCLUSION

Community-led health promotion initiatives may have had some benefits on chronic condition risk factors, including stabilisation of body composition, in this remote Indigenous community. Given that less favourable trends were observed for diabetes and total cholesterol over a short time period and smoking prevalence remained high, policy initiatives that address social and economic disadvantage are needed alongside community-led health promotion initiatives.

Chronic kidney disease and socio-economic status: a cross sectional study

Objective: This cross-sectional study investigated the relationship between individual-level markers of disadvantage, renal function and cardio-metabolic risk within an Indigenous population characterised by a heavy burden of chronic kidney disease and disadvantage.Design: Using data from 20 Indigenous communities across Australia, an aggregate socio-economic status (SES) score was created from individual-level socio-economic variables reported by participants. Logistic regression was used to assess the association of individual-level socio-economic variables and the SES score with kidney function (an estimated glomerular function rate (eGFR) cut-point of <60 ml/min/1.73 m²) as well as clinical indicators of cardio-metabolic risk.Results: The combination of lower education and unemployment was associated with poorer kidney function and higher cardio-metabolic risk factors. Regression models adjusted for age and gender showed that an eGFR < 60 ml/min/1.73 m² was associated with a low socio-economic score (lowest vs. highest 3.24 [95% CI 1.43-6.97]), remote living (remote vs. highly to moderately accessible 3.24 [95% CI 1.28-8.23]), renting (renting vs. owning/being purchased 5.76[95% CI 1.91-17.33]), unemployment (unemployed vs employed 2.85 [95% CI 1.31-6.19]) and receiving welfare (welfare vs. salary 2.49 [95% CI 1.42-4.37]). A higher aggregate socio-economic score was inversely associated with an eGFR < 60 ml/min/1.73 m² (0.75 [95% CI 063-0.89]).Conclusion: This study extends upon our understanding of associations between area-level markers of disadvantage and burden of end stage kidney disease amongst Indigenous populations to a detailed analysis of a range of well-characterised individual-level factors such as overall low socio-economic status, remote living, renting, unemployment and welfare. With the increasing burden of end-stage kidney disease amongst Indigenous people, the underlying socio-economic conditions and social and cultural determinants of health need to be understood at an individual as well as community-level, to develop, implement, target and sustain interventions.

Health-related behaviours in a remote Indigenous population with Type 2 diabetes: a Central Australian primary care survey in the Telehealth Eye and Associated Medical Services Network [TEAMSnet] project

AIM

There is a wealth of data concerning the health behaviours of Indigenous Australians, but the health behaviours of Indigenous Australians with diabetes are not systematically documented. At the clinical level, understanding a person's health behaviours can help identify and address barriers to diabetes care and promote good clinical outcomes.

METHODS

We used a novel survey tool to systematically collect health behaviour data on Smoking, Nutrition, Alcohol consumption, Physical activity and Emotional well-being (SNAPE) from Indigenous Australians with Type 2 diabetes in a remote primary care setting in Alice Springs.

RESULTS

At least one of the five surveys in the SNAPE tool was completed by 210 participants: 30% male, mean age 52.6 years (range 22.9 - 87.4). Fifty per cent of men and 23% of women were current smokers (P < 0.001). None of the participants reported an adequate intake of vegetables. Only 9.6% reported an adequate fruit intake. Some 49% of men and 32% of women consumed alcohol in the past year (P = 0.022), and 46% of drinkers were considered high-risk or likely-dependent drinkers. On average, participants walked 10 min or more at a time 6.0 days a week and spent 4.8 h sitting on a weekday. Mean adapted Patient Health Questionnaire 9 score was 4.61, with 34% of participants having mild depressive symptoms and 11% having moderate-severe depressive symptoms.

CONCLUSIONS

Our SNAPE survey tool results present a high-risk, disadvantaged Indigenous population with Type 2 diabetes. More resources will be needed to sustainably implement interventions with the goal of improving health behaviours and subsequent long-term health.

Diabetes care in remote Australia: the antenatal, postpartum and inter-pregnancy period

BACKGROUND

Aboriginal and Torres Strait Islander women experience high rates of diabetes in pregnancy (DIP), contributing to health risks for mother and infant, and the intergenerational cycle of diabetes. By enhancing diabetes management during pregnancy, postpartum and the interval between pregnancies, the DIP Partnership aims to improve health outcomes and reduce risks early in the life-course. We describe a mixed methods formative study of health professional's perspectives of antenatal and post-partum diabetes screening and management, including enablers and barriers to care.

METHODS

Health professionals involved in providing diabetes care in pregnancy, from a range of health services across the Northern Territory, completed the survey (n = 82) and/or took part in interviews and/or focus groups (n = 62).

RESULTS

Qualitative findings highlighted factors influencing the delivery of care as reported by health professionals, including: whose responsibility it is, access to care, the baby is the focus and pre-conception care. The main challenges were related to: disjointed systems and confusion around whose role it is to provide follow-up care beyond six weeks post-partum. Quantitative findings indicated that the majority of health professionals reported confidence in their own skills to manage women in the antenatal period (62%, 40/79) and slightly lower rates of confidence in the postpartum interval (57%, 33/58).

CONCLUSION

These findings regarding whose role it is to provide postpartum care, along with opportunities to improve communication pathways and follow up care have informed the design of a complex health intervention to improve health systems and the provision of DIP related care.

Real-world experience of metformin use in pregnancy: Observational data from the Northern Territory Diabetes in Pregnancy Clinical Register

BACKGROUND

In Australia's Northern Territory, Indigenous mothers account for 33% of births and have high rates of hyperglycemia in pregnancy. The prevalence of type 2 diabetes (T2D) in pregnancy is up to 10-fold higher in Indigenous than non-Indigenous Australian mothers, and the use of metformin is common. We assessed birth outcomes in relation to metformin use during pregnancy from a clinical register.

METHODS

The study included women with gestational diabetes (GDM), newly diagnosed diabetes in pregnancy (DIP), or pre-existing T2D from 2012 to 2016. Data were analyzed for metformin use in the third trimester. Regression models were adjusted for maternal age, body mass index, parity, and insulin use.

RESULTS

Of 1649 pregnancies, 814 (49.4%) were to Indigenous women, of whom 234 (28.7%) had T2D (vs 4.6% non-Indigenous women; P < 0.001). Metformin use was high in Indigenous women (84%-90% T2D, 42%-48% GDM/DIP) and increased over time in non-Indigenous women (43%-100% T2D, 14%-35% GDM/DIP). Among Indigenous women with GDM/DIP, there were no significant differences between groups with and without metformin in cesarean section (51% vs 39%; adjusted odds ratio [aOR] 1.25, 95% confidence interval [CI] 0.87-1.81), large for gestational age (24% vs 13%; aOR 1.5, 95% CI 0.9-2.5), or serious neonatal adverse events (9.4% vs 5.9%; aOR 1.32, 95% CI 0.68-2.57). Metformin use was independently associated with earlier gestational age (37.7 vs 38.5 weeks), but the risk did not remain independently higher after exclusion of women managed with medical nutrition therapy alone, and the increase in births <37 weeks was not significant on multivariate analysis.

CONCLUSIONS

We found no clear evidence of any adverse outcomes related to the use of metformin for the treatment of hyperglycemia in pregnancy.

Associations between Community Environmental-Level Factors and Diet Quality in Geographically Isolated Australian Communities

Remote Indigenous Australians experience disproportionately poor cardio-metabolic health, which is largely underpinned by adverse dietary intake related to social determinants. Little evidence exists about the community environmental-level factors that shape diet quality in this geographically isolated population group. This study aimed to explore the modifiable environmental-level factors associated with the features of dietary intake that underpin cardio-metabolic disease risk in this population group. Community-level dietary intake data were estimated from weekly store sales data collected throughout 2012 and linked with concurrent social, built, and physical environmental dimension data for 13 remote Indigenous Australian communities in the Northern Territory. Statistical analyses were performed to investigate associations. At the community level, store sales of discretionary foods were lower in communities with greater distance to a neighbouring store (r = −0.45 (p < 0.05)). Sales of sugar-sweetened beverages were lower in communities with higher levels of household crowding (r = −0.55 (p < 0.05)), higher levels of Indigenous unemployment (r = −0.62 (p = 0.02)), and greater distance to neighbouring stores (r = −0.61 (p = 0.004)). Modifiable environmental-level factors may be associated with adverse diet quality in remote Indigenous Australian communities and further investigations of these factors should be considered when developing policies to improve dietary intake quality in geographically isolated populations.

Is hyperfiltration associated with higher urine albumin-to-creatinine ratio at follow up among Indigenous Australians? The eGFR follow-up study

BACKGROUND

Glomerular hyperfiltration is not able to be detected in clinical practice. We assessed whether hyperfiltration is associated with albuminuria progression among Indigenous Australians at high risk of diabetes and kidney disease to determine its role in kidney disease progression.

METHODS

Longitudinal observational study of Indigenous Australians aged ≥18 years recruited from >20 sites, across diabetes and/or kidney function strata. At baseline, iohexol clearance was used to measure glomerular filtration rate (mGFR) and hyperfiltration was defined as (i) a mGFR of ≥125 mL/min/1.73 m², and (ii) an age-adjusted definition, with the top 10% of the mGFR for each 10 year age group at baseline. Baseline and follow-up urine albumin-to-creatinine ratio (uACR) was collected, and linear regression was used to assess the associations of hyperfiltration and uACR at follow up.

RESULTS

407 individuals (33% men, mean age 47 years) were followed-up for a median of 3 years. At baseline, 234 had normoalbuminuria and 173 had albuminuria. Among participants with normoalbuminuria, those with mGFR ≥125 mL/min/1.73 m² had 32% higher uACR at follow-up (p = 0.08), and those with age-adjusted hyperfiltration had 60% higher uACR (p = 0.037) compared to those who had normofiltration. These associations were independent of uACR at baseline, but attenuated by HbA_1c. Associations were stronger among those without than those with albuminuria at baseline.

CONCLUSIONS

Although not available for assessment in current clinical practice, hyperfiltration may represent a marker of subsequent albuminuria progression among individuals who have not yet developed albuminuria.

Maternal body mass index, excess gestational weight gain, and diabetes are positively associated with neonatal adiposity in the Pregnancy and Neonatal Diabetes Outcomes in Remote Australia (PANDORA) study

BACKGROUND

In-utero exposures likely influence the onset and severity of obesity in youth. With increasing rates of type 2 diabetes mellitus (T2DM) and maternal adiposity in pregnancy globally, it is important to assess the impact of these factors on neonatal adipose measures.

OBJECTIVES

To evaluate the contribution of maternal ethnicity, body mass index (BMI), gestational weight gain, and hyperglycaemia to neonatal adiposity.

METHODS

Pregnancy and Neonatal Diabetes Outcomes in Remote Australia (PANDORA) is a longitudinal cohort study of Australian mother and neonate pairs. In this analysis, Indigenous (n = 519) and Europid (n = 358) women were included, of whom 644 had hyperglycaemia (type 2 diabetes [T2DM], diabetes in pregnancy [DIP], or gestational diabetes [GDM]). Associations between maternal ethnicity, hyperglycaemia, BMI and gestational weight gain, and the neonatal outcomes of length, head circumference, sum of skinfolds, total body fat, and percentage body fat were examined. Models were adjusted for maternal age, smoking status, parity, education, neonatal gender, and gestational age.

RESULTS

Among those with hyperglycaemia in pregnancy, Indigenous women had a higher proportion of T2DM and DIP (36%, 13%) compared with Europid women (4%, 3%). In multivariate analysis, maternal T2DM (compared with no hyperglycaemia), BMI during pregnancy, and excess compared with appropriate gestational weight gain, were significantly associated with greater neonatal measures. DIP was associated with greater sum of skinfolds, total body fat, and percentage body fat. Indigenous ethnicity was associated with greater sum of skinfolds.

CONCLUSIONS

Maternal BMI, excess gestational weight gain, and hyperglycaemia operated as independent factors influencing neonatal adiposity. Interventions addressing these factors are needed to reduce neonatal adiposity.

Vitamin D status and the risk of type 2 diabetes: The Melbourne Collaborative Cohort Study

AIMS

Inverse associations between vitamin D status and risk of type 2 diabetes observed in epidemiological studies could be biased by confounding and reverse causality. We investigated the prospective association between vitamin D status and type 2 diabetes and the possible role of reverse causality.

METHODS

We conducted a case-cohort study within the Melbourne Collaborative Cohort Study (MCCS), including a random sample of 628 participants who developed diabetes and a sex-stratified random sample of the cohort (n = 1884). Concentration of 25-hydroxyvitamin D (25(OH)D) was measured using liquid chromatography-tandem mass spectrometry in samples collected at recruitment. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of type 2 diabetes for quartiles of 25(OH)D relative to the lowest quartile and per 25 nmol/L increase in 25(OH)D, adjusting for confounding variables.

RESULTS

The ORs for the highest versus lowest 25(OH)D quartile and per 25 nmol/L increase in 25(OH)D were 0.60 (95% CI: 0.44, 0.81) and 0.76 (95% CI: 0.63, 0.92; p = 0.004), respectively. In participants who reported being in good/very good/excellent health approximately four years after recruitment, ORs for the highest versus lowest 25(OH)D quartile and per 25 nmol/L increase in 25(OH)D were 0.46 (95% CI: 0.29, 0.72) and 0.71 (95% CI: 0.56, 0.89; p = 0.003), respectively.

CONCLUSIONS

In this sample of middle-aged Australians, vitamin D status was inversely associated with the risk of type 2 diabetes, and this association did not appear to be explained by reverse causality.

Sugar-sweetened beverage (SSB) consumption, correlates and interventions among Australian Aboriginal and Torres Strait Islander communities: a scoping review

OBJECTIVES

Sugar-sweetened beverage (SSB) consumption in Australian Aboriginal and Torres Strait Islander people is reported to be disproportionally high compared with the general Australian population. This review aimed to scope the literature documenting SSB consumption and interventions to reduce SSB consumption among Australian Aboriginal and Torres Strait Islander people. Findings will inform strategies to address SSB consumption in Aboriginal and Torres Strait Islander communities.

METHODS

PubMed, SCOPUS, CINAHL, Informit, Joanna Briggs Institute EBP, Mura databases and grey literature were searched for articles published between January 1980 and June 2018. Studies were included if providing data specific to an Australian Aboriginal and/or Torres Strait Islander population's SSB consumption or an intervention that focused on reducing SSB consumption in this population.

DESIGN

Systematic scoping review.

RESULTS

59 articles were included (1846 screened). While reported SSB consumption was high, there were age-related and community-related differences observed in some studies. Most studies were conducted in remote or rural settings. Implementation of nutrition interventions that included an SSB component has built progressively in remote communities since the 1980s with a growing focus on community-driven, culturally sensitive approaches. More recent studies have focused exclusively on SSB consumption. Key SSB-related intervention elements included incentivising healthier options; reducing availability of less-healthy options; nutrition education; multifaceted or policy implementation (store nutrition or government policy).

CONCLUSIONS

There was a relatively large number of studies reporting data on SSB consumption and/or sales, predominantly from remote and rural settings. During analysis it was subjectively clear that the more impactful studies were those which were community driven or involved extensive community consultation and collaboration. Extracting additional SSB-specific consumption data from an existing nationally representative survey of Aboriginal and Torres Strait Islander people could provide detailed information for demographic subgroups and benchmarks for future interventions. It is recommended that a consistent, culturally appropriate, set of consumption measures be developed.

Cost effectiveness and cost-utility analysis of a group-based diet intervention for treating major depression - the HELFIMED trial

Background/objectives: Major depression has a negative impact on quality of life, increasing the risk of premature death. It imposes social and economic costs on individuals, families and society. Mental illness is now the leading cause globally of disability/lost quality life and premature mortality. Finding cost-effective treatments for depression is a public health priority. We report an economic evaluation of a dietary intervention for treating major depression. Methods: This economic evaluation drew on the HELFIMED RCT, a 3-month group-based Mediterranean-style diet (MedDiet) intervention (including cooking workshops), against a social group-program for people with major depression. We conducted (i) a cost-utility analysis, utility scores measured at baseline, 3-months and 6-months using the AQoL8D, modelled to 2 years (base case); (ii) a cost-effectiveness analysis, differential cost/case of depression resolved (to normal/mild) measured by the DASS. Differential program costs were calculated from resources use costed in AUD2017. QALYs were discounted at 3.5%pa. Results: Best estimate differential cost/QALY gain per person, MedDiet relative to social group was AUD2775. Probabilistic sensitivity analysis, varying costs, utility gain, model period found 95% likelihood cost/QALY less than AUD20,000. Estimated cost per additional case of depression resolved, MedDiet group relative to social group was AUD2,225. Conclusions: A MedDiet group-program for treating major depression was highly cost-effective relative to a social group-program, measured in terms of cost/QALY gain and cost per case of major depression resolved. Supporting access by persons with major depression to group-based dietary programs should be a policy priority. A change to funding will be needed to realise the potential benefits.

Health-Promoting Food Pricing Policies and Decision-Making in Very Remote Aboriginal and Torres Strait Islander Community Stores in Australia

Aboriginal and Torres Strait Islander people living in remote communities in Australia experience a disproportionate burden of diet-related chronic disease. This occurs in an environment where the cost of store-purchased food is high and cash incomes are low, factors that affect both food insecurity and health outcomes. Aboriginal and Torres Strait Islander storeowners and the retailers who work with them implement local policies with the aim of improving food affordability and health outcomes. This paper describes health-promoting food pricing policies, their alignment with evidence, and the decision-making processes entailed in their development in community stores across very remote Australia. Semi-structured interviews were conducted with a purposive sample of retailers and health professionals identified through the snowball method, September 2015 to October 2016. Data were complemented through review of documents describing food pricing policies. A content analysis of the types and design of policies was undertaken, while the decision-making process was considered through a deductive, thematic analysis. Fifteen retailers and 32 health professionals providing services to stores participated. Subsidies and subsidy/price increase combinations dominated. Magnitude of price changes ranged from 5% to 25% on fruit, vegetables, bottled water, artificially sweetened and sugar sweetened carbonated beverages, and broadly used 'healthy/essential' and 'unhealthy' food classifications. Feasibility and sustainability were considered during policy development. Greater consideration of acceptability, importance, effectiveness and unintended consequences of policies guided by evidence were deemed important, as were increased involvement of Aboriginal and Torres Strait Islander storeowners and nutritionists in policy development. A range of locally developed health-promoting food pricing policies exist and partially align with research-evidence. The decision-making processes identified offer an opportunity to incorporate evidence, based on consideration of the local context.

Contribution of cardiometabolic risk factors to estimated glomerular filtration rate decline in Indigenous Australians with and without albuminuria - the eGFR Follow-up Study

AIM

We assessed associations between cardiometabolic risk factors and estimated glomerular filtration rate (eGFR) decline according to baseline albuminuria to identify potential treatment targets in Indigenous Australians.

METHODS

The eGFR Follow-up Study is a longitudinal cohort of 520 Indigenous Australians. Linear regression was used to estimate associations between baseline cardiometabolic risk factors and annual Chronic Kidney Disease Epidemiology Collaboration eGFR change (mL/min per 1.73m² /year), among those classified with baseline normoalbuminuria (urine albumin-to-creatinine ratio (uACR) <3 mg/mmol; n = 297), microalbuminuria (uACR 3-30 mg/mmol; n = 114) and macroalbuminuria (uACR ≥30 mg/mmol; n = 109).

RESULTS

After a median of 3 years follow-up, progressive declines of the age- and sex-adjusted mean eGFR were observed across albuminuria categories (-2.0 [-2.6 to -1.4], -2.5 [-3.7 to -1.3] and -6.3 [-7.8 to -4.9] mL/min per 1.72m² /year). Although a borderline association was observed between greater baseline haemoglobin A_1c and eGFR decline in those with macroalbuminuria (P = 0.059), relationships were not significant in those with microalbuminuria (P = 0.187) or normoalbuminuria (P = 0.23). Greater baseline blood pressure, C-reactive protein, waist-to-hip ratio and lower high-density lipoprotein cholesterol showed non-significant trends with greater eGFR decline in the presence of albuminuria.

CONCLUSION

Over a 3 year period, marked eGFR decline was observed with greater baseline albuminuria. Cardiometabolic risk factors were not strong predictors for eGFR decline in Indigenous Australians without albuminuria. Longer follow-up may elucidate the role of these predictors and other mechanisms in chronic kidney disease progression in this population.

Improving postpartum screening after diabetes in pregnancy: Results of a pilot study in remote Australia

BACKGROUND

The postpartum period is a critical time to improve health outcomes for Aboriginal women, particularly for those who have chronic conditions.

AIMS

To assess enhanced support methods (for women following diabetes in pregnancy (DIP)) to improve completion rates of recommended postpartum health checks.

MATERIALS AND METHODS

Fifty-three Aboriginal women in the Northern Territory (NT) were contacted in the postpartum period to encourage medical check-ups. Messages were delivered through phone (call or text messages) or other methods (Facebook or email). The primary outcome was postpartum blood glucose testing (oral glucose tolerance testing (OGTT), random or fasting glucose and HbA1c).

RESULTS

Establishing contact with women was difficult. Of 137 messages sent to 52 women, 22 responded (42%). Phone was the most common contact method with successful contact made from 16 of 119 (13%) attempts. Rates of postpartum OGTT completion were higher in the group successfully contacted (32% vs 7%). However, for any postpartum glucose testing (including OGTT and HbA1c) rates were 25 of 42 (60%) and neither success in making contact nor the contact method was associated with higher rates.

CONCLUSIONS

The small sample size limits our conclusions; however, results highlight that engaging remote women postpartum is difficult. While rates of postpartum OGTT completion differed according to successful contacts, rates of any postpartum blood glucose testing did not. Further research is needed to explore feasible intervention methods to improve postpartum screening after a pregnancy complicated by diabetes.

The AUStralian MEDiterranean Diet Heart Trial (AUSMED Heart Trial): A randomized clinical trial in secondary prevention of coronary heart disease in a multiethnic Australian population: Study protocol

The Mediterranean diet was first characterized as a heart-protective diet in the 1960s. The significant cardioprotective effects of the Mediterranean diet in comparison to the standard-care low-fat diet have been established in the primary prevention of cardiovascular disease (CVD); however, there is insufficient evidence in secondary prevention research to influence the current standard of care. Opportunity exists to assess the Mediterranean diet as a therapeutic target for secondary CVD prevention within Australia's ethnoculturally diverse communities. The AUSMED Heart Trial is a multisite randomized controlled trial that will evaluate the efficacy of the Mediterranean diet for secondary prevention of CVD in the Australian health care setting. This trial aims to evaluate the effect of a 6-month Mediterranean diet intervention (delivered by dietitians) versus a "standard-care" low-fat diet in reducing the composite incidence of cardiovascular events at 12 months and at trial end in participants with documented evidence of a previous acute myocardial infarction at trial entry. The quality of the diet at baseline and follow-up will be assessed using comprehensive dietary questionnaires and diaries as well as relevant dietary biomarkers (such as urinary polyphenols and erythrocyte fatty acids). Cardiovascular risk markers, including novel measures of immune and inflammatory status, endothelial function, vascular compliance, platelet activity, and body composition, will be collected to explore possible mechanisms for treatment effect. Cost-effectiveness will also be estimated to support policy translation. We plan to recruit 1,032 participants (516 per arm) from cardiology clinics in major Australian hospitals in Melbourne, Adelaide, and Brisbane.

Dietary intervention for people with mental illness in South Australia

Background

People with serious mental illness (SMI) have a 25-30 year lower life expectancy than the general population due largely to cardiovascular disease (CVD). Mediterranean diet can reduce CVD risk and repeat events by 30-70%. We conducted a pilot feasibility study (HELFIMED) with people who have SMI residing within a Community Rehabilitation Centre in South Australia, aimed at improving participants' diets according to Mediterranean diet principles.

Methods

During a 3-month intervention, participants were provided with nutrition education, food hampers, and twice-weekly cooking workshops and guided shopping trips. This report presents the results of a mixed method evaluation of the programme using thorough in-depth interviews with participants and support staff (n = 20), contextualized by changes in dietary biomarkers and CVD risk factors.

Results

The framework thematic analysis revealed evidence of improvements in participants' knowledge of and intake of the key elements of a Mediterranean-style diet (fruit and vegetables, olive oil, fish, legumes), reduction in poor nutrition habits (soft drinks, energy drinks, take away meals) and development of independent living skills-culinary skills such as food preparation and cooking based on simple recipes, food shopping and budgeting, healthy meal planning and social interaction. These changes were supported by dietary biomarkers, and were associated with reduced CVD risk factors.

Conclusions

A Mediterranean diet-based pilot study achieved positive change in dietary behaviours associated with CVD risk for participants with SMI. This supports a need to include dietary education and cooking skills into rehabilitation programmes for people with SMI.

Cross-sectional associations of albuminuria among Aboriginal and Torres Strait Islander adults: the eGFR Study

OBJECTIVE

To describe the detailed associations of albuminuria among a contemporary cohort of Aboriginal and Torres Strait Islander people to inform strategies for chronic kidney disease prevention and management.

METHODS

A cross-sectional analysis of Indigenous participants of the eGFR Study.

MEASURES

Clinical, biochemical and anthropometric measures were collected (including body-circumferences, blood pressure (BP); triglycerides, HbA1c, liver function tests, creatinine; urine- microscopic-haem, albumin: creatinine ratio (ACR), prescriptions- angiotensin converting enzyme inhibitor or angiotensin receptor II antagonist (ACEI/ARB). Albuminuria and diabetes were defined by an ACR>3.0 mg/mmol, and HbA1c≥48 mmol/mol or prior history respectively. Waist: hip ratio (WHR), and estimated glomerular filtration rate (eGFR) were calculated. ACR was non-normally distributed; a logarithmic transformation was applied (in base 2), with each unit increase in log2-albuminuria representing a doubling of ACR.

RESULTS

591 participants were assessed (71% Aboriginal, 61.6% female, mean age 45.1 years, BMI 30.2 kg/m² , WHR 0.94, eGFR 99.2 ml/min/1.73m² ). The overall prevalence of albuminuria, diabetes, microscopic-haem and ACEI/ARB use was 41.5%, 41.5%, 17.8% and 34.7% respectively; 69.3% of adults with albuminuria and diabetes received an ACEI/ARB. Using multivariable linear regression modelling, the potentially modifiable factors independently associated with log2-albuminuria were microscopic-haem, diabetes, WHR, systolic BP, alkaline phosphatase (all positive) and eGFR (inverse).

CONCLUSION

Albuminuria is associated with diabetes, central obesity and haematuria. High ACEI/ARB prescribing for adults with diabetes and albuminuria was observed. Further understanding of the links between fat deposition, haematuria and albuminuria is required.

High Baseline Levels of Tumor Necrosis Factor Receptor 1 Are Associated With Progression of Kidney Disease in Indigenous Australians With Diabetes: The eGFR Follow-up Study

OBJECTIVE

To examine the association between soluble tumor necrosis factor receptor 1 (sTNFR1) levels and kidney disease progression in Indigenous Australians at high risk of kidney disease.

RESEARCH DESIGN AND METHODS

This longitudinal observational study examined participants aged ≥18 years recruited from >20 sites across diabetes and/or kidney function strata. Baseline measures included sTNFR1, serum creatinine, urine albumin-to-creatinine ratio (uACR), HbA_1c, C-reactive protein (CRP), waist-to-hip ratio, systolic blood pressure, and medical history. Linear regression was used to estimate annual change in estimated glomerular filtration rate (eGFR) for increasing sTNFR1, and Cox proportional hazards were used to estimate the hazard ratio (HR) and 95% CI for developing a combined renal outcome (first of a ≥30% decline in eGFR with a follow-up eGFR <60 mL/min/1.73 m², progression to renal replacement therapy, or renal death) for increasing sTNFR1.

RESULTS

Over a median of 3 years, participants with diabetes (n = 194) in the highest compared with the lowest quartile of sTNFR1 experienced significantly greater eGFR decline (-4.22 mL/min/1.73 m²/year [95% CI -7.06 to -1.38]; P = 0.004), independent of baseline age, sex, eGFR, and uACR. The adjusted HR (95% CI) for participants with diabetes per doubling of sTNFR1 for the combined renal outcome (n = 32) was 3.8 (1.1-12.8; P = 0.03). No association between sTNFR1 and either renal outcome was observed for those without diabetes (n = 259).

CONCLUSIONS

sTNFR1 is associated with greater kidney disease progression independent of albuminuria and eGFR in Indigenous Australians with diabetes. Further research is required to assess whether TNFR1 operates independently of other metabolic factors associated with kidney disease progression.

A Mediterranean-style dietary intervention supplemented with fish oil improves diet quality and mental health in people with depression: A randomized controlled trial (HELFIMED)

OBJECTIVES

We investigated whether a Mediterranean-style diet (MedDiet) supplemented with fish oil can improve mental health in adults suffering depression.

METHODS

Adults with self-reported depression were randomized to receive fortnightly food hampers and MedDiet cooking workshops for 3 months and fish oil supplements for 6 months, or attend social groups fortnightly for 3 months. Assessments at baseline, 3 and 6 months included mental health, quality of life (QoL) and dietary questionnaires, and blood samples for erythrocyte fatty acid analysis.

RESULTS

n = 152 eligible adults aged 18-65 were recruited (n = 95 completed 3-month and n = 85 completed 6-month assessments). At 3 months, the MedDiet group had a higher MedDiet score (t = 3.95, P < 0.01), consumed more vegetables (t = 3.95, P < 0.01), fruit (t = 2.10, P = 0.04), nuts (t = 2.29, P = 0.02), legumes (t = 2.41, P = 0.02) wholegrains (t = 2.63, P = 0.01), and vegetable diversity (t = 3.27, P < 0.01); less unhealthy snacks (t = -2.10, P = 0.04) and red meat/chicken (t = -2.13, P = 0.04). The MedDiet group had greater reduction in depression (t = -2.24, P = 0.03) and improved mental health QoL scores (t = 2.10, P = 0.04) at 3 months. Improved diet and mental health were sustained at 6 months. Reduced depression was correlated with an increased MedDiet score (r = -0.298, P = 0.01), nuts (r = -0.264, P = 0.01), and vegetable diversity (r = -0.303, P = 0.01). Other mental health improvements had similar correlations, most notably for increased vegetable diversity and legumes. There were some correlations between increased omega-3, decreased omega-6 and improved mental health.

DISCUSSION

This is one of the first randomized controlled trials to show that healthy dietary changes are achievable and, supplemented with fish oil, can improve mental health in people with depression.

Barriers and facilitators for health professionals referring Aboriginal and Torres Strait Islander tobacco smokers to the Quitline

OBJECTIVE

To examine the barriers and facilitators among health professionals to providing referrals to Quitline for Aboriginal and Torres Strait Islander clients who smoke.

METHODS

A brief online survey, based on the Theoretical Domains Framework, was completed by 34 health professionals who work with Aboriginal and Torres Strait Islander people in South Australia and the Northern Territory.

RESULTS

Respondents who frequently made referrals had higher domain scores than less frequent referrers for 'Skills and knowledge' (M=4.44 SD=0.39 vs. M=4.09 SD=0.47, p<0.05) and 'beliefs about capabilities' (M=4.33 SD=0.44 vs. M=3.88 SD=0.42, p<0.01). Barriers to providing referrals to Quitline were lack of client access to a phone, cost of a phone call, preference for face-to-face interventions, and low client motivation to quit.

CONCLUSIONS

Health professionals working with Aboriginal and Torres Strait Islander clients should be supported to build their skills and confidence to provide referrals to Quitline and other brief cessation interventions. Building capacity for face-to-face support locally would be beneficial where phone support is not preferable. Implications for public health: Engaging with health professionals who work with Aboriginal and Torres Strait Islander people to increase referrals to Quitline is strategic as it builds on their existing capacity to provide cessation support.

A comparison of dietary estimates from the National Aboriginal and Torres Strait Islander Health Survey to food and beverage purchase data

OBJECTIVE

We compared self-reported dietary intake from the very remote sample of the National Aboriginal and Torres Strait Islander Nutrition and Physical Activity Survey (VR-NATSINPAS; n=1,363) to one year of food and beverage purchases from 20 very remote Indigenous Australian communities (servicing ∼8,500 individuals).

METHODS

Differences in food (% energy from food groups) and nutrients were analysed using t-test with unequal variance.

RESULTS

Per-capita energy estimates were not significantly different between the surveys (899 MJ/person/day [95% confidence interval -152,1950] p=0.094). Self-reported intakes of sugar, cereal products/dishes, beverages, fats/oils, milk products/dishes and confectionery were significantly lower than that purchased, while intakes of meat, vegetables, cereal-based dishes, fish, fruit and eggs were significantly higher (p<0.05).

CONCLUSION

Differences between methods are consistent with differential reporting bias seen in self-reported dietary data. Implications for public health: The NATSINPAS provides valuable, much-needed information about dietary intake; however, self-reported data is prone to energy under-reporting and reporting bias. Purchase data can be used to track population-level food and nutrient availability in this population longitudinally; however, further evidence is needed on approaches to estimate wastage and foods sourced outside the store. There is potential for these data to complement each other to inform nutrition policies and programs in this population.

How effective are family-based and institutional nutrition interventions in improving children's diet and health? A systematic review

BACKGROUND

Effective strategies to improve dietary intake in young children are a priority to reduce the high prevalence of chronic non-communicable diseases in adulthood. This study aimed to assess the impact of family-based and school/preschool nutrition programs on the health of children aged 12 or younger, including the sustainability of these impacts and the relevance to socio-economic inequalities.

METHODS

A systematic review of literature published from 1980 to December 2014 was undertaken. Randomised controlled trials involving families with children aged up to 12 years in high income countries were included. The primary outcomes were dietary intake and health status. Results were presented in a narrative synthesis due to the heterogeneity of the interventions and outcomes.

RESULTS

The systematic search and assessment identified 39 eligible studies. 82% of these studies were set in school/preschools. Only one school study assessed the impact of involving parents systematically. The family-based programs which provided simple positive dietary advice to parents and regular follow-up reduced fat intake significantly. School and family-based studies, if designed and implemented well, increased F&V intake, particularly fruit. Effective school-based programs have incorporated role-models including peers, teachers and heroic figures, rewards and increased access to healthy foods. School nutrition programs in disadvantaged communities were as effective as programs in other communities.

CONCLUSIONS

Family and school nutrition programs can improve dietary intake, however evidence of the long-term sustainability of these impacts is limited. The modest overall impact of even these successful programs suggest complementary nutrition interventions are needed to build a supportive environment for healthy eating generally.

Bilirubin concentration is positively associated with haemoglobin concentration and inversely associated with albumin to creatinine ratio among Indigenous Australians: eGFR Study

Low serum bilirubin concentrations are reported to be strongly associated with cardio-metabolic disease, but this relationship has not been reported among Indigenous Australian people who are known to be at high risk for diabetes and chronic kidney disease (CKD).

HYPOTHESIS

serum bilirubin will be negatively associated with markers of chronic disease, including CKD and anaemia among Indigenous Australians.

METHOD

A cross-sectional analysis of 594 adult Aboriginal and Torres Strait Islander (TSI) people in good health or with diabetes and markers of CKD. Measures included urine albumin: creatinine ratio (ACR), estimated glomerular filtration rate (eGFR), haemoglobin (Hb) and glycated haemoglobin (HbA1c). Diabetes was defined by medical history, medications or HbA1c≥6.5% or ≥48mmol/mol. Anaemia was defined as Hb<130g/L or <120g/L in males and females respectively. A multivariate regression analysis examining factors independently associated with log-bilirubin was performed.

RESULTS

Participants mean (SD) age was 45.1 (14.5) years, and included 62.5% females, 71.7% Aboriginal, 41.1% with diabetes, 16.7% with anaemia, 41% with ACR>3mg/mmol and 18.2% with eGFR<60mL/min/1.73m². Median bilirubin concentration was lower in females than males (6 v 8μmol/L, p<0.001) and in Aboriginal than TSI participants (6 v 9.5μmol/L, p<0.001). Six factors explained 35% of the variance of log-bilirubin; Hb and cholesterol (both positively related) and ACR, triglycerides, Aboriginal ethnicity and female gender (all inversely related).

CONCLUSION

Serum bilirubin concentrations were positively associated with Hb and total cholesterol, and inversely associated with ACR. Further research to determine reasons explaining lower bilirubin concentrations among Aboriginal compared with TSI participants are needed.

Factors Associated with Routine Dental Attendance among Aboriginal Australians

OBJECTIVES

To determine factors associated with routine dental attendance in Aboriginal Australians.

METHODS

Data of 271 Aboriginal adults residing in Australia's Northern Territory were used. Routine dental attendance was defined as last visiting a dentist less than one year ago or visiting a dentist for a check-up. Both bivariate and multivariable analytical techniques were used.

RESULTS

While 27% visited a dentist in the past year, 29% of these visited for a check-up. In bivariate analysis, being female, low psychological distress, and low clinical attachment loss (CAL) were associated with visiting a dentist within last year. Being aged younger than 39 years, male, no oral health impairment, being caries-free, low CAL, and low apolipoprotein B were associated with visiting for a check-up. Clinical attachment loss remained associated with visiting a dentist less than one year ago while being younger than 39 years and having no oral health impairment remained associated with usually visiting for a check-up in multivariable analysis.

CONCLUSIONS

Younger age, no oral health impairment, and low CAL were associated with routine dental attendance among Indigenous Australians.

Associations of mortality and cardiovascular disease risks with diabetes and albuminuria in urban Indigenous Australians: the DRUID follow-up study

AIM

To assess the relationships of diabetes and albuminuria with all-cause mortality and cardiovascular disease outcomes in a population without prior cardiovascular disease using data from the Darwin Region Urban Indigenous Diabetes (DRUID) study.

METHODS

We conducted a prospective cohort study of 706 participants (aged 15-81 years, 68% women) without prior cardiovascular disease who underwent a 75-g oral glucose tolerance test. Deaths and fatal or non-fatal cardiovascular disease were determined over 7 years, and hazard ratios with 95% CIs and population attributable risks were estimated for baseline glycaemia and albuminuria.

RESULTS

Compared with normoglycaemia and after adjustment for age, sex, hypertension, dyslipidaemia and smoking, known diabetes was associated with an adjusted hazard ratio of 4.8 (95% CI 1.5-14.7) for all-cause mortality and 5.6 (95% CI 2.1-15.2) for cardiovascular disease. Compared with normoalbuminuria, the respective adjusted risks for macroalbuminuria were 10.9 (95% CI 3.7-32.1) and 3.9 (95% CI 1.4-10.8). The Adjusted all-cause mortality and cardiovascular disease estimated population attributable risks for diabetes were 27% and 32%, and for albuminuria they were 32% and 21%, respectively.

CONCLUSIONS

In our study population, the burden of mortality and cardiovascular disease was largely driven by diabetes and albuminuria. This finding on the influence of diabetes and albuminuria is consistent with reports in other high-risk Indigenous populations and should be better reflected in risk scores and intervention programmes.

Impact of perinatal exposure to sucrose or high fructose corn syrup (HFCS-55) on adiposity and hepatic lipid composition in rat offspring

KEY POINTS

Fructose-containing sugars, including sucrose and high fructose corn syrup (HFCS), have been implicated in the epidemics of obesity and type 2 diabetes. Few studies have evaluated the impact of perinatal exposure to these sugars on metabolic and physiological outcomes in the offspring. Using a rat model, offspring exposed to a maternal sucrose or HFCS diet during the prenatal and/or suckling periods were found to have altered adiposity and liver fat content and composition at weaning. Plasma levels of free fatty acids remained elevated in young adulthood, but consumption of a control diet following weaning appeared to ameliorate most other effects of perinatal exposure to a maternal high-sugar diet. Guidelines for maternal nutrition should advise limiting consumption of fructose-containing sugars, and it is particularly important that these recommendations include maternal nutrition during lactation.

ABSTRACT

Perinatal exposure to excess maternal intake of added sugars, including fructose and sucrose, is associated with an increased risk of obesity and type 2 diabetes in adult life. However, it is unknown to what extent the type of sugar and the timing of exposure affect these outcomes. The aim of this study was to determine the impact of exposure to maternal consumption of a 10% (w/v) beverage containing sucrose or high fructose corn syrup-55 (HFCS-55) during the prenatal and/or suckling periods on offspring at 3 and 12 weeks, utilising a cross-fostering approach in a rodent model. Perinatal sucrose exposure decreased plasma glucose concentrations in offspring at 3 weeks, but did not alter glucose tolerance. Increased adiposity was observed in 3-week-old offspring exposed to sucrose or HFCS-55 during suckling, with increased hepatic fat content in HFCS-55-exposed offspring. In terms of specific fatty acids, hepatic monounsaturated (omega-7 and -9) fatty acid content was elevated at weaning, and was most pronounced in sucrose offspring exposed during both the prenatal and suckling periods, and HFCS-55 offspring exposed during suckling only. By 12 weeks, the effects on adiposity and hepatic lipid composition were largely normalised. However, exposure to either sucrose or HFCS-55 during the prenatal period only was associated with elevated plasma free fatty acids at weaning, and this effect persisted until 12 weeks. This study suggests that the type of sugar and the timing of exposure (prenatal or suckling periods) are both important for determining the impact on metabolic health outcomes in the offspring.

Low rates of predominant breastfeeding in hospital after gestational diabetes, particularly among Indigenous women in Australia

OBJECTIVES

To investigate rates of 'any' and 'predominant' breastfeeding in hospital among Indigenous and non-Indigenous women with and without gestational diabetes mellitus (GDM).

METHODS

A retrospective study of singleton infants born from July 2007 to December 2010 at Cairns Hospital, Australia, following GDM pregnancy, using linked hospital and birth data (n=617 infants), with a subsample of medical record reviews (n=365 infants). Aggregate data were used to compare to breastfeeding rates among infants born following non-GDM pregnancy (n=7,894 infants).

RESULTS

More than 90% of all women reported any breastfeeding before hospital discharge. About 80% of women without GDM reported predominant breastfeeding. Despite significant increases over time (p<0.0001), women with GDM were less likely to predominantly breastfeed (OR 0.32, 95%CI 0.27-0.38, p<0.0001); with lower rates among Indigenous women (53%) compared with non-Indigenous (60%) women (OR 0.78, 0.70-0.88, p<0.0001); and women having a caesarean birth or pre-term infant.

CONCLUSIONS

Rates of predominant in-hospital breastfeeding were lower among women with GDM, particularly among Indigenous women and women having a caesarean or pre-term birth.

IMPLICATIONS

Strategies are needed to support predominant in-hospital breastfeeding among women with GDM.

Comparison of creatinine and cystatin C based eGFR in the estimation of glomerular filtration rate in Indigenous Australians: The eGFR Study

BACKGROUND

The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation that combines creatinine and cystatin C is superior to equations that include either measure alone in estimating glomerular filtration rate (GFR). However, whether cystatin C can provide any additional benefits in estimating GFR for Indigenous Australians, a population at high risk of end-stage kidney disease (ESKD) is unknown.

METHODS

Using a cross-sectional analysis from the eGFR Study of 654 Indigenous Australians at high risk of ESKD, eGFR was calculated using the CKD-EPI equations for serum creatinine (eGFRcr), cystatin C (eGFRcysC) and combined creatinine and cystatin C (eGFRcysC+cr). Reference GFR (mGFR) was determined using a non-isotopic iohexol plasma disappearance technique over 4h. Performance of each equation to mGFR was assessed by calculating bias, % bias, precision and accuracy for the total population, and according to age, sex, kidney disease, diabetes, obesity and c-reactive protein.

RESULTS

Data were available for 542 participants (38% men, mean [sd] age 45 [14] years). Bias was significantly greater for eGFRcysC (15.0mL/min/1.73m²; 95% CI 13.3-16.4, p<0.001) and eGFRcysC+cr (10.3; 8.8-11.5, p<0.001) compared to eGFRcr (5.4; 3.0-7.2). Accuracy was lower for eGFRcysC (80.3%; 76.7-83.5, p<0.001) but not for eGFRcysC+cr (91.9; 89.3-94.0, p=0.29) compared to eGFRcr (90.0; 87.2-92.4). Precision was comparable for all equations. The performance of eGFRcysC deteriorated across increasing levels of c-reactive protein.

CONCLUSION

Cystatin C based eGFR equations may not perform well in populations with high levels of chronic inflammation. CKD-EPI eGFR based on serum creatinine remains the preferred equation in Indigenous Australians.

Food and beverage price discounts to improve health in remote Aboriginal communities: mixed method evaluation of a natural experiment

OBJECTIVE

Retrospectively evaluate food price discounts in remote Aboriginal community stores.

METHODS

Four price discount strategies of 10% were designed in 2010, aiming to influence grocery, fruit, vegetables and diet soft-drink sales. This natural experiment across a group of stores was evaluated using an explanatory, sequential mixed method design through analysis of store point-of-sale, document, observation and interview data. The outcome was measured by change in: 1) percentage of grocery sales to total food and beverage; 2) fruit and vegetable sales; and 3) diet soft-drink sales. Qualitative data enabled the interpretation of outcomes through understanding perceived success and benefits, and enablers and barriers to implementation.

RESULTS

Eighteen community stores and 54 informants participated. While targeted price discounts were considered important to improving health, no discernible effect was evident, due to inadequate design and communication of discount promotion, and probably inadequate magnitude of discount.

CONCLUSIONS

Strategy impact on food and beverage sales was limited by promotion and magnitude of discount. Implication for Public Health: This study demonstrates key factors and commitment required to design, communicate, implement and monitor strategies to improve health in this challenging remote retail context. Evaluation of natural experiments can contribute evidence to policy-making.

Use of the Bayer DCA 2000+ for the measurement of glycated haemoglobin in a remote Australian Aboriginal community

Background: Good glycaemic control in type 2 diabetes can reduce both morbidity and mortality, and monitoring of glycated haemoglobin A1c (HbA1c) is currently recommended for this purpose.

Methods: Haemoglobin A1c can be measured using the portable Bayer DCA 2000+. As part of a community-based screening project for chronic diseases, subjects with impaired fasting glucose concentrations or diabetes had their HbA1c concentration measured on the analyser. HbA1c measurements were also made in a laboratory using cation-exchange high-performance liquid chromatography. Results were then compared to those obtained in the field. HbA1c values were loge transformed to obtain a normal distribution.

Results: Mean (95% confidence interval) HbA1c measured on the DCA 2000+ ( n = 39) was 6.3% (5.8, 6.9%), while that measured in the laboratory was 6.5% (6.0, 7.0%). The correlation coefficient ( r) between the measurements was 0.96 ( P < 0.01). Bland-Altman analysis revealed that the DCA 2000+ estimate of HbA1c could be used interchangeably with that from the laboratory (mean bias = 0.1%, limits of agreement - 1.1, 0.8%). The sensitivity, specificity and positive predictive value of the DCA 2000+ estimate of HbA1c using a cut-off value of <7% for adequate glycaemic control, were all 100%.

Conclusions: The DCA 2000+ may be used to measure HbA1c in remote communities.

Anthropometric indices and their relationship with diabetes, hypertension and dyslipidemia in Australian Aboriginal people and Torres Strait Islanders

BACKGROUND

Australian indigenous people have a body shape and cardiovascular risk profiles different from that of other ethnic populations. This present study aims to examine the association of anthropometric indices with diabetes, hypertension and dyslipidemia, and to determine what indices can best predict these individual risk factors for the risk of cardiovascular disease (CVD).

DESIGN

A cross-sectional study of Australian Aboriginal people and Torres Strait Islanders.

METHODS

A total of 747 Australian Aboriginal people and 439 Torres Strait Islanders aged 25 years and over were examined between 1993 and 1997. Body weight, height, waist and hip circumferences, blood pressure, plasma glucose, triglycerides, total and high-density lipoprotein cholesterol were measured.

RESULTS

The best predictor of hypertension among five anthropometric indices was waist : height ratio for Australian Aboriginal people and waist circumference for Torres Strait Islanders. Waist : hip ratio (WHR) was the best predictor for both diabetes and dyslipidemia in both populations. In multivariate regression analyses, WHR and body mass index were independently associated with the 10-year predicted absolute probability of coronary heart disease (CHD) for Torres Strait Islanders. However, overall WHR appeared to be the best predictor of the estimated CHD risk for both populations.

CONCLUSIONS

This study shows that WHR was the best predictor for diabetes, dyslipidemia and absolute CHD risk in Australian Aboriginal people and Torres Strait Islanders. Incorporating WHR into routine health examinations in Australian indigenous people will enhance the evaluation of CVD risk.

People with schizophrenia and depression have a low omega-3 index

Cardiovascular disease (CVD) is higher in people with mental illness and is associated with a 30 year higher mortality rate in this population. Erythrocyte docosahexaenoic acid (DHA) plus eicosapentaenoic acid (EPA) (omega-3 index)≤4% is a marker for increased mortality risk from CVD while >8% is protective. Omega-3 polyunsaturated fatty acids are also important for brain function and may ameliorate symptoms of mental illness. We investigated the erythrocyte omega-3 index in people with mental illness. One hundred and thirty adults aged 18-65 years (32.6% male) with schizophrenia (n=14) and depression (n=116) provided blood samples and completed physiological assessments and questionnaires. Both populations had risk factors for metabolic syndrome and CVD. The average omega-3 index was 3.95% (SD=1.06), compared to an estimated 5% in the Australian population. These data indicate an unfavourable omega-3 profile in people with mental illness that could contribute to higher CVD risk.

Progression of Kidney Disease in Indigenous Australians: The eGFR Follow-up Study

BACKGROUND AND OBJECTIVES

Indigenous Australians experience a heavy burden of CKD. To address this burden, the eGFR Follow-Up Study recruited and followed an Indigenous Australian cohort from regions of Australia with the greatest ESRD burden. We sought to better understand factors contributing to the progression of kidney disease. Specific objectives were to assess rates of progression of eGFR in Indigenous Australians with and without CKD and identify factors associated with a decline in eGFR.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This observational longitudinal study of Indigenous Australian adults was conducted in >20 sites. The baseline cohort was recruited from community and primary care clinic sites across five strata of health, diabetes status, and kidney function. Participants were then invited to follow up at 2-4 years; if unavailable, vital status, progression to RRT, and serum creatinine were obtained from medical records. Primary outcomes were annual eGFR change and combined renal outcome (first of ≥30% eGFR decline with follow-up eGFR<60 ml/min per 1.73 m(2), progression to RRT, or renal death).

RESULTS

Participants (n=550) were followed for a median of 3.0 years. Baseline and follow-up eGFR (geometric mean [95% confidence interval], 83.9 (80.7 to 87.3) and 70.1 (65.9 to 74.5) ml/min per 1.73 m(2), respectively. Overall mean annual eGFR change was -3.1 (-3.6 to -2.5) ml/min per 1.73 m(2). Stratified by baseline eGFR (≥90, 60-89, <60 ml/min per 1.73 m(2)), annual eGFR changes were -3.0 (-3.6 to -2.4), -1.9 (-3.3 to -0.5), and -5.0 (-6.5 to -3.6) ml/min per 1.73 m(2). Across baseline eGFR categories, annual eGFR decline was greatest among adults with baseline albumin-to-creatinine ratio (ACR) >265 mg/g (30 mg/mmol). Baseline determinants of the combined renal outcome (experienced by 66 participants) were higher urine ACR, diabetes, lower measured GFR, and higher C-reactive protein.

CONCLUSIONS

The observed eGFR decline was three times higher than described in nonindigenous populations. ACR was confirmed as a powerful predictor for eGFR decline across diverse geographic regions.

Periodontal therapy and glycaemic control among individuals with type 2 diabetes: reflections from the PerioCardio study

OBJECTIVES

Diabetes mellitus and periodontal disease are highly prevalent among Indigenous Australian adults. Untreated periodontitis impacts glycaemic control in people with diabetes. The aim of this study was to report on the effect of periodontal therapy on glycaemic control among people with obesity.

METHODS

This subgroup analysis is limited to 62 participants with diabetes from the original 273 Aboriginal Australian adults enrolled into the PerioCardio study. Intervention participants received full-mouth non-surgical periodontal scaling during a single, untimed session while controls were untreated. Endpoints of interest included change in glycated haemoglobin (HbA1c), C-reactive protein (CRP) and periodontal status at 3 months post-intervention.

RESULTS

There were more females randomized to the treatment group (n = 17) than control (n = 10) while the control group had a higher overall body mass index (BMI) [mean (SD)] 33.1 (9.7 kg m^-2 ) versus 29.9 (6.0 kg m^-2 ). A greater proportion of males were followed up at 3 months compared to females, P = 0.05. Periodontal therapy did not significantly reduce HbA1c: ancova difference in means 0.22 mmol mol^-1 (95% CI -6.25 to 6.69), CRP: ancova difference in means 0.64 (95% CI -1.08, 2.37) or periodontal status at 3 months.

CONCLUSIONS

Non-surgical periodontal therapy did not significantly reduce glycated haemoglobin in participants with type 2 diabetes. Reasons are likely to be multifactorial and may be influenced by persistent periodontal inflammation at the follow-up appointments. Alternatively, the BMI of study participants may impact glycaemic control via alternative mechanisms involving the interplay between inflammation and adiposity meaning HbA1c may not be amenable to periodontal therapy in these individuals.

Resting heart rate, physiological stress and disadvantage in Aboriginal and Torres Strait Islander Australians: analysis from a cross-sectional study

Background

Lower socioeconomic status has been linked to long-term stress, which can manifest in individuals as physiological stress. The aim was to explore the relationship between low socioeconomic status and physiological stress in Aboriginal and Torres Strait Islander Australians.

Methods

Using data from the eGFR Study (a cross-sectional study of 634 Indigenous Australians in urban and remote areas of northern and central Australia), we examined associations between resting heart rate and demographic, socioeconomic, and biomedical factors. An elevated resting heart rate has been proposed as a measure of sustained stress activation and was used as a marker of physiological stress. Relationships were assessed between heart rate and the above variables using univariate and multiple regression analyses.

Results

We reported a mean resting heart rate of 74 beats/min in the cohort (mean age 45 years). On multiple regression analysis, higher heart rate was found to be independently associated with Aboriginal ethnicity, being a current smoker, having only primary level schooling, higher HbA1c and higher diastolic blood pressure (model R² 0.25).

Conclusions

Elevated resting heart rate was associated with lower socioeconomic status and poorer health profile in Aboriginal and Torres Strait Islander Australians. Higher resting heart rate may be an indicator of stress and disadvantage in this population at high risk of chronic diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0211-9) contains supplementary material, which is available to authorized users.

Nutritional predictors of chronic disease in a Central Australian Aboriginal cohort: A multi-mixture modelling analysis

BACKGROUND AND AIMS

Chronic diseases (including diabetes, cardiovascular disease, hypertension and chronic kidney disease) are major contributors to the total burden of disease for Aboriginal people. Here we used novel epidemiological modelling to investigate nutritional profiles at a population level associated with chronic disease.

METHODS AND RESULTS

Multi-mixture modelling, was used to group members of a Central Australian Aboriginal population (n = 444) based on their nutritional profile from a risk factor prevalence survey in 1995. Multi-mixture modelling assigned % membership to four classes; Class 1 (young, low adiposity and lipids, low dietary antioxidants; n = 171.7); Class 2 (older, greater adiposity and lipids; n = 22.6); Class 3 (predominantly female, greater adiposity and antioxidants, low smoking; n = 134.3) and Class 4 (predominantly male, greater lipids and adiposity, low antioxidants, high smoking prevalence; n = 115.4). For persons free of chronic disease (n = 285), incident chronic disease for classes 1, 3 and 4 was determined using follow up hospital, primary health care and death records collected in 2004/05. Fifty-four percent of Class 4 had incident chronic disease, an excess of 3355 events per 100,000 person years relative to Class 1. Incident CVD, hypertension, or CKD was highest for Class 4 and incident diabetes highest for Class 3.

CONCLUSION

Multi-mixture modelling appears useful in identifying population subgroups of an Aboriginal population at risk of chronic conditions.

Type 2 diabetes after gestational diabetes: greater than fourfold risk among Indigenous compared with non-Indigenous Australian women

BACKGROUND

Gestational diabetes is associated with a high risk of type 2 diabetes. However, progression rates among Indigenous women in Australia who experience high prevalence of gestational diabetes are unknown.

METHODS

This retrospective cohort study includes all births to women at a regional hospital in Far North Queensland, Australia, coded as having 'gestational diabetes' from 1 January 2004 to 31 December 2010 (1098 births) and receiving laboratory postpartum screening from 1 January 2004 to 31 December 2011 (n = 483 births). Women who did not receive postpartum screening were excluded from the denominator. Data were linked between hospital electronic records, routinely collected birth data and laboratories, with sample validation by reviews of medical records. Analysis was conducted using Cox-proportional regression models.

RESULTS

Indigenous women had a greater than fourfold risk of developing type 2 diabetes within 8 years of having gestational diabetes, compared with non-Indigenous women (hazards ratio 4.55, 95% confidence interval 2.63-7.88, p < 0.0001). Among women receiving postpartum screening tests, by 3, 5 and 7 years postpartum, 21.9% (15.8-30.0%), 25.5% (18.6-34.3%) and 42.4% (29.6-58.0%) Indigenous women were diagnosed with type 2 diabetes after gestational diabetes, respectively, compared with 4.2% (2.5-7.2%), 5.7% (3.3-9.5%) and 13.5% (7.3-24.2%) non-Indigenous women. Multivariate analysis showed an increased risk of developing type 2 diabetes among women with an early pregnancy body mass index ≥25 kg/m(2) , only partially breastfeeding at hospital discharge and gestational diabetes diagnosis prior to 17 weeks gestation.

CONCLUSIONS

This study demonstrates that, compared with non-Indigenous women, Indigenous Australian women have a greater than fourfold risk of developing type 2 diabetes after gestational diabetes. Strategies are urgently needed to reduce rates of type 2 diabetes by supporting a healthy weight and breastfeeding and to improve postpartum screening among Indigenous women with gestational diabetes. Copyright © 2015 John Wiley & Sons, Ltd.